Ex-Protégé Criticizes Buffett Over Exit

By

Serena Ng and

Jean Eaglesham

Jan. 4, 2013 6:47 p.m. ET

Former Berkshire Hathaway Inc. executive David Sokol had harsh words for his onetime mentor, billionaire investor Warren Buffett, the day after Mr. Sokol was notified he wouldn't face regulatory action for his trading activities.

Mr. Sokol was once seen as a potential successor to Mr. Buffett, but his shot at running the Omaha, Neb., conglomerate ended with his resignation in March 2011 amid disclosures he had personally purchased...